Selective switch



Jan. 18, 1944. K. 1.. FREDERICK SELECTIVE SWITCH 2 Sheets-Sheet 1 Filed Jan. 6, 1943 mzi4icliiii zi$ 2 INVEN TOR K L. FREDERICK A T TOR/VEV Jan. 18, 1944.

K. L. FREDERICK SELECTIVE SWITCH Filed Jan. 6, 1943 2 Sheets-Sheet 2 FIG. a

FIG. 5

w l/EN TOR K. L FREDERICK ATTORNEY Patented Jan. 18, 1944 SELECTIVE SWITCH Kenneth L. Frederick, Berwyn, 111., assignor to Western Electric Company, Incorporated, New York, N. Y., a corporation of New York Application January 6, 1943, Serial No. 471,424

Claims.

This invention relates to switching mechanisms and particularly to such mechanisms as are used in automatic telephone systems and known as crossbar switches.

An object is to improve and simplify such cross bar switches to reduce the number of actuating magnets and to increase their capacity and utility.

Heretofore so-called three-dimensional cross bar switching arrangements have been provided in which connections are established in three stages of operations. Such switches may consist of a number of cross bar switches of the usual well-known type in which the operation of a select bar in one coordinate direction followed by the operation of a hold bar in the other coordinate direction establishes connections between contacts at the intersecting point of said two bars. Such a switch structure may be arranged with a plurality of groups of select bars and a single group of hold bars and means whereby a first operation selects one select bar in each of the plurality of groups in one of which the desired connection will be made by the aid of the selected bar, whereby a second operation actuates one of said selected bars and whereby a third operation selects a hold bar. Such a switching arrangement is shown, for example, in the patent to C. L. Goodrum et a1. 1,528,763 of March 10, 1925. Other arrangements have been employed in which special types of cross bar switches are arranged one above the other for three-dimensional selections. In such arrangements the selections were made by operating the contact strips themselves, through the medium of a select bar extending through correspond ing cross-points of succeeding switches selected and operated by another common cross bar switch. Thus in this case a three-dimensional organization of operate bars and contacts was obtained.

The present invention relates to an arrangement which to some extent partakes of the principles of both of these two types of switches.

A feature of the invention is an arrangement of layers of coordinate contact strips one layer on top of another with three major groups of operating bars each major group arranged in a plurality of minor groups with the minor groups arranged in layers on top of each other and with a magnet for operating each layer of bars. Mechanism is provided whereby the operation of one magnet from each major group will establish a connection at any cross-point of contact strips in any layer of such strips. This invention maybe carried out, for example, by having the coordinate sets of contact strip layers located in a horizontal plane and provide a horizontal primary select bar and a horizontal hold bar associated with and running parallel with each set of contact strips in one coordinate direction in each horizontal layer, and a row of secondary select bars for each vertical field of crosspoints with each select bar in a row running through succeeding corresponding cross-points of succeeding horizontal layers of coordinate sets of contact strips. A magnet and a control bar is provided for each horizontal layer of primary select bars for the rotation thereof, a magnet and a control bar is provided for each vertical row of secondary select bars for the rotation thereof and a magnet and a control bar is also provided for each row of hold bars for the rotation thereof. Means are also provided at each cross-point whereby a connection at any crosspoint of sets of contact strips may be accomplished by actuating a group of primary select bars, a group of secondary select bars and a group of hold bars intersecting said cross-point. The arrangement at each cross-point is therefore such that the primary select bar shifts a lever, the secondary select bar turns this lever to shift a select finger associated with the hold bar in a position where the hold bar when actuated causes it to move one set of the coordinate contact strips at this cross-point in connection with the other set to establish the connections.

Referring now to the drawings:

Fig. 1 shows in a diagrammatic form the general layout of a three-dimensional cross bar switching mechanism in accordance with applicants invention.

Fig. 2 shows primarily the mechanism at a cross-point of two coordinate sets of contacts;

Fig. 3 is a fragmentary top view of the mechanism at two such cross-points as shown in Fig. 2.

Fig. 4 is a partial cross-section taken approximately on lines 4-4 of Fig. 3;

Fig. 5 is a side view cross-section taken approximately along the lines 5-5 of Fig. 3;

Fig. 6 is a view similar to Fig. 4 except that the operating bars are shown in actuated position.

Reference is now made particularly to Fig. 1. This figure shows in general th layout of the operating mechanism embodying the applicants invention and in which the various bars and operating members for the bars have been indicated by single lines. The showing in this figure represents a switch having a 10 by 10 by 10 ca,-

pacity that is there would be a total of one thousand cross-points. The primary select bars may be arranged in ten horizontal planes, each plane containing ten parallel bars in a row. The first bar of the lower plane and the first bar of the upper plane have been indicated respectively by the numerals'l and 2. The ten bars in each horizontal plane are rotatable in unison by a primary select magnet through the mechanism of a horizontally located operate rod shiftable longitudinally. The primary select magnet 3 and associated operate rod d for the lower row of ten primary select bars has been shown as well as the primary select magnet 5 and associated operate bar 6 for the upper row of ten primary select bars. Similarly, the intermediate primary select magnets and operate rods will control the intermediate horizontal rows of ten bars. Similarly, there are secondary select bars arranged in ten Vertical planes at right angle to the horizontal planes of primary select bars with ten bars in a row in each plane. The first bar in the first row is marked and the last or tenth bar in this row is shown partially and marked H. The ten secondary select bars in each row are rotatable by a secondary select magnet through the medium of an operate rod. The secondary select magnet for the first row is marked 12 and the operate rod is marked 23 and the last or tenth select magnet in this row is marked Hi and the operate rod is marked 15. Running parallel with each primary select bar, there is a hold bar. The first bar of th ten in the lower horizontal plane is marked 20. These bars are rotatable in a different grouping. That is, each vertical row of ten hold bars is rotated by a corresponding operate rod and hold magnet such as rod 2| for the first vertical row controlled by hold magnet 22 and rod 2:1 and hold magnet 25 for the last or tenth vertical row of hold bars. Thus it will be seen that with a switch structure as described in this figure, there would be ten horizontal rows of ten each of the primary select bars and hold bars and ten vertical rows of ten each of secondary select bars with ten primary magnets each operating ten primary select bars andten secondary magnets each operating ten secondary select bars and ten hold magnets Y each operating ten hold bars.

It should be further observed that if one primary select magnet, one secondary select magnet and one hold magnet are operated, the bars controlled by these three magnets which intersect each other at a common cross-point will cause operations to take place that result in establishing of connections between contact strips at this crosspoint. The contact strip arrangement for this purpose will now be described followed by a .description of the exact mechanical details at each cross-point of these three groups of bars for actuating said strips to establish connections. There may be ten horizontal layers of coordinate strips one on top of the other. In each layer or plane, one coordinate group of strips will run in the same direction as the operating rods l3 and I5 and the other group will run perpendicular to this first group. In other words, there will be one thousand cross-points of contact strips in this switch structure, each point of which may be selectable as described hereinafter. As shown in Figs. 2 to 6, the contact strip arrangement in each horizontal layer may consist of two coordinate groups of such strips with ten sets of contact strips in each group and each set may consist of three strips. One set of one coordinate group is indicated by the numeral 29 and a set of the other coordinate group is marked 35). These groups of strips are embedded or assembled between insulation sheets as shown in ,Fig. 3 and indicated by the general number 3!. In Fig. 4, for example, a cross section is shown at 32 through these two sets of contact strips and insulation sheets. The insulation sheets and strips may be held in place by bushings or eyelets such as 35 at various places. flat and of a rectangular cross section, while the strips 39 are of similar shape but with cutout flexible sections, such as 36, for movement to connect with the stationary strips 29, respectively, as indicated in this Fig. 3 and Fig. 4 at the intersecting point 3?. The insulation sheets 3! are provided with cut-outs such as shown at 38 in Fig. 3 at each cross-point for the free passage of bars and other parts as will be described hereinafter for various purposes. The description of the mechanism at a cross-point may begin by stating that a primary select bar such as 39 is pivoted at one end at it and similarly pivoted at the opposite end for rotation. This bar has a downwardly extending projection 42 provided with a slot d3 through which an operating rod or wire 44- is inserted. This wire may be associated at one end with an extension on an armature d5 controlled by a primary magnet 46, All of the primary bars in one horizontal plane are controlled by a common primary magnet to be rotated thereby through the medium of this operating rod M and magnet 46. On the righthand side of the bar 39 at each cross-point as shown in Figs. 2 and 3 is a fork-shaped extension 19 which is associated with an insulation member 59 by engaging slots such as 5! and 52 on opposite sides thereof so that when the primary select bar is rotated, these projections 49 will lower the insulation members 53. All of the insulation members controlled by bar 39 are mounted as shown on succeeding secondary select bars such as the secondary select bars 55 shown in Fig. 3. Each of these secondary bars extend through insulation members such as 53 associated with the different primary select bars located on on top of the other in the different layers. Each secondary select bar thus holds ten insulation members such as 50. These secondary select bars are pivoted at the top and at the bottom of the structure as shown, for example, at 56 and 51 for rotation and each bar is provided with an angular forwardly extending projection 59 provided with a slot 60 in which the operating rod or wire BI is connected. All secondary select bars located in each vertical row at right angles to the primary select bars are connected together by means of an operating rod such as 6|. Rod (ii is connected to an extension from an armature 62 controlled by a secondary select magnet 63 so that the secondary select magnet 53, for example, operates on ten secondary select bars to rotate them simultaneously. On the rotation of any select bar, the associated members 56 are also rotaltzed for a purpose that will be described hereina er.

Running parallel with each primary select bar is a corresponding hold bar, one of which is shown in Fig. 3 and indicated by a numeral 65 pivoted at one end at 66 and similarly pivoted at the other end for rotation. This hold bar is provided with an angular projection 61 having a slot 68 in which an operating rod 69 is secured and extends to hold bars located one on top of the other in the same vertical row. This rod 69 is connected to an extension on armature The contact strips 29 are H controlled by hold magnet 12 so that each hold magnet will rotate ten hold bars in a corresponding vertical row. The hold bar 65 is also provided at each cross-point with a projection extending towards the left marked 14 and another projection extending toward the right marked 15. The projection 14 is bent upward at 16 and to this upward extension is connected the select finger or wire 18 which normally rests in the slot 8| in an upwardly extending extension 82 from extension 15. This finger is tensioned to engage the right-hand lower corner of the slot 8| as shown at 84 in Fig. 3. To the cutout movable spring portions 36 of the contact strips and near the free ends thereof is con nected an operating card 86. Each spring is located in a separate slot 81 in the upper portion 88 of the card. The lower part 89 of the card is widened at the bottom and provided with a transverse slot 90 in which the part SI of the extension 82 may enter. The part 92 of the extension 82 looking at Fig. 3 extends on one side of the card portion 89.

A description will now be made of the operation of this mechanism to select and establish a connection at any one of the cross-points. The first operation that takes place is the actuation of a primary select magnet such as 46 to attract its armature and thereby have the rod 44 rotate the associated primary select bars. If reference is made to Fig. 2, for example, the select rod shown therein and marked 39 may be one of these primary select bars. The operation of these primary select bars will lower all the associated insulating members 50 on all of the secondary select bars such as where they cross these primary select bars, that is, each primary select bar will lower ten insulating members 50 on ten secondary select bars. By the operation of one of these primary magnets therefore, one horizontal group or layer of coordinate contact strips have been preselected from which further selections will be made, that is, one hundred cross-points have been preselected by the operation of one primary select magnet, and subsequent selections will therefore be made from these one hundred cross-points. The next operation will be to select ten cross-points in these one hundred by rotating one group of secondary select bars by the operation of a corresponding secondary select magnet such as 63 which will operate on its armature 62 to cause the operating wire 6| to rotate the secondary select bar 55 as shown in Fig. 2 and the other nine in the same vertical plane. It will be noted now that these secondary select bars that have been rotated have each one associated insulation member 50 in the horizontal plane in which the corresponding primary select bars are operated. By the operation of this secondary select magnet, therefore, a group of ten cross-points in this plane have been selected from which a further selection will be made.

The operation of a secondary select rod will, as stated, rotate its associated insulation members 50 and the ten insulation members 58 that have been shifted will now act on the associated fingers such as T8 to move them in their slots 8| sideways, looking at Figs. 3 and 5 or towards the left looking at Fig. 2 from normal position against edge 84 to a position against edge 94 on the portion 9| of extension 82. That is, the ten vertical secondary select bars operated will move ten fingers to operated positions. The next step will be to operate a hold bar which is accomplished by causing, for example, the hold magnet 12 to attract its armature H to pull the rod 69 downwardly as shown in Fig. 2 and rotate the associated hold bar 65 and the nine other hold bars controlled by this rod 69 in a vertical direction. Only one of these hold bars, for example 65, will have one of its select fingers shifted by the operated primary and secondary select bars and thus be effective to raise this shifted finger to engage the under-side of the card such as 86 and cause this card to be raised to control the associated cut-out spring members 36 to connect, respectively, with the associated contact strips 29 at this particular crosspoint. The other hold bars operated will not perform any useful functions as the fingers associated with these bars have not been shifted but will merely be raised to take positions on the right side of the associated cards looking at Fig. 5. The operated hold bars will now remain actuated to maintain the established connection at this cross-point but the primary and secondary select magnets may now release the associated select bars. It should be noted that further con.- nections may be made in this cross bar switch arrangement except at the cross-points where the fingers have been raised. On the other hand establishing of these other connections at other cross-points will not interfere with the previously established connection as the secondary select bars are always returned to normal after each operation, the fingers shifted in the slots 8| will be restored to their normal positions and the fingers raised at the previous connections will merely be shifted sideways into slots such as 96 in the associated cards 86 in normal. It may therefore be seen that with this mechanism at ten out of one thousand cross-points, connections may be made between coordinate contact strips with the connections concentrated in one horiozntal plane of such strips or distributed over all ten planes in any combination by the operation of one magnet from each of three groups of ten magnets representing hundreds, tens and units selections in automatic telephone systems.

What is claimed is:

1. In a cross bar switch, horizontal layers of contact strips, one layer on top of another and with the contact strips in each layer arranged in two groups intersecting each other at right angles, a hold bar and a primary select bar associated and running parallel with each contact strip in one of said groups in each horizontal layer, a secondary select bar at each cross-point of the two groups of contact strips of a layer and running vertically through said corresponding cross-points in all layers and located between the associated hold bar and primary select bar at said cross-points, means for rotating all primary select bars in any horizontal layer in unison, means for rotating all secondary select bars in any vertical row of such bars in unison comprising the bars associated with one of the contact strips of the group in each horizontal layer which is located perpendicular to the hold bars and select bars, means for rotating all of the hold bars in any vertical row of said bars, and means responsive to the rotation of one group of primary select bars, one group of secondary select bars and one group of hold bars for establishing a connection between a strip in one group and a strip in the other group in the same horizontal layer at the cross-point of said strips as determined by the primary, secondary and hold bars rotated in this layer.

2. In a cross bar switch, horizontal layer of contact strips, one layer on top of another and with the contact strips in each layer arranged in sets in two groups intersecting each other at right angles, a hold bar and a primary select bar associated and running parallel with each contact strip in one of said groups in each horizontal layer, a secondary select bar at each cross-point of the sets in two groups of contact strips of a layer and running vertically through said corresponding cross-points in all layers and located between the associated hold bar and primary select bar at said cross-points, a select finger associated with each hold bar at each point where it crosses a secondary select bar, a slidable memher on each secondary select bar at each point where it crosses a hold bar, a projection on each primary select bar at each point where it crosses a secondary select bar engaging the associated slidable member, said select fin ers, slidable members and projection at each cross-point are so rotated that on the rotation of a primary select bar, the projections thereon move the slidable members of the associated secondary select bars in front of the associated fingers on the associated hold bar so that when an associated secondary select bar rotates it shifts through the medium of its moved slidable member the associated finger, and when the associated hold bar rotates the shifted finger is moved to actuate the sets of contact strips at this cross-point to establish connections between them.

3. In a cross bar switch, a plurality of layers of contact strips, each layer comprising two coordinately arranged groups of strips, a system of operating bars in which two groups or" bars are arranged in layers in parallel with the contact strip layers, and a third group of bars are arranged in layers perpendicular to the layers of strips, means for actuating a layer of bars from each of said three groups of bars, and means operative in response to the operation of said three groups of bars for establishing a connection between the particular strips from each group in a particular layer of strips as determined by the particular bars in said three groups that are actuated.

4. In a cross bar switch, horizontal layers of contact strips, one layer on top of another and with the contact strip in each'layer arranged in two groups intersecting each other at right angles, one of said groups being flexible for movements into contact with the associated contact strip at each cross-point, a hold bar and a primary select bar associated and running parallel with each contact strip in one of said groups in each horizontal layer, a secondary select bar at each cross-point of the two groups of contact strips of a layer and running vertically through said corresponding cross-points in all layers and located between the associated hold bar and primary select bar at said cross-points, and means at each of said cross-points comprising a select finger mounted on the hold bar, an operating card mounted on the movable strip, a cam member slidably mounted on the secondary select bar, a projecting operating member on the primary select bar, said parts being so arranged in relation to each other that on the operation of the primary select bar the cam member is shifted on the secondary select bars so that on a subsequent operation of the secondary select bar shifted cam member will shift the select finger so that it will enter between the hold bar and the card into a position where the hold bar when operated will lift the card through the medium of the finger to shift the movable strip in contact with the stationary strip,

5. In a cross bar switch, horizontal mounting plates with one plate on top of another, sets of contact strips with one strip on top of another in each set, a plurality of such strips mounted on each plate in two coordinate groups and so arranged that Where one set of one group intersects the set of another group corresponding strips of one group may be selected and flexed for movement to contact respectively with corresponding stationary strips of the other group, a primary select bar and a hold bar mounted under each plate in parallel relation to each set of flexible contact strips, a secondary select bar running vertically through apertures in all of said plates, one such secondary select bar being located between a pair of associated primary select bars and hold bars of each plate at the cross-point of the associated sets of contact strips of each plate, a magnet and means for rotating in unison each group of primary select bars for each plate, a magnet and means for rotating in unison all hold bars in each vertical row, a magnet and means for rotating in unison all secondary select bars in each row of such bars formed by the bars located in line with each set of stationary contact strips, means at each cross-point of a stationary set of contact strips and a flexible set of associated contact strips comprising a select finger mounted on the hold member, an operating card mounted on the flexible contact strips, a cam slidably mounted on the secondary select bar and a projecting operating memberon the primary select bar'engaging the cam, said bars being so coordinated in relation to each other than when the primary select bar is rotated the projecting operating members shift the cam in position to engage the finger, that when the secondary select bar rotates the cam it shifts the finger in position between the hold bar and the card and that on the subsequent rotation of the hold bar it will through the media of this finger lift the card to cause the flexible contact strips to connect respectively with the associated stationary contact strips and maintain this connection after the primary and secondary select bars are returned to normal.

KENNETH L. FREDERICK. 

